cake/Collection bug with generators and iterators

iter.php

<?php

$gen = function() {
	yield 1;
};

$iter = new IteratorIterator($gen());
$ngen = $iter->getInnerIterator();

class ReplaceIterator extends IteratorIterator
{
	private $cb;
	
	function __construct($iter, $cb) {
		parent::__construct($iter);
		$this->cb = $cb;
	}
	
	function current() {
		$cb = $this->cb;
		return $cb(parent::current());
	}
}

$filter = new ReplaceIterator($ngen, function($a){ return $a; });

iterator_to_array($filter, false);